looking for the ghosts of dark matter past…

Not that long ago, I wrote an open letter to the Standard Model, the theoretical, in the scientific sense of the word, framework that describes the structure and behavior of particles that make up the universe as we know it. While this letter confirmed many of is successes, especially with the confirmation of the Higgs boson, it referred to the need for it to somehow be broken for the world of physics to move forward, citing knowledge of something that lay beyond it. Considering that it was a pretty vague reference, I thought it would be a good idea to revisit it and elaborate as to why we need something beyond the Standard Model to explain the universe. Yes, parts of the problem have to do with the transition between quantum and classical states which we are still trying to understand, but the bigger problem is the vast chasm between the masses of each and every particle covered by the model and the mass associated with gravity taking over from the quantum world and responsible for the cosmos as we know it on a macro scale.

So why is the Higgs some 20 orders of magnitude too light to help explain the gap between the behavior of quantum particles and the odd gravitational entities that we’re pretty sure make up the fabric of space and time? Well, the answer to that is that we really don’t know. There are a few ideas, one in vogue right now gives new life to a nearly 40 year old hypothesis of a particle known as an axion. The thought is that low mass particles with no charge just nudged the mass of the Higgs into what it is today during the period of extremely rapid inflation right after the Big Bang, creating the gap we see today, rather than holding on to the idea that the Higgs came to exist at its current mass of 125 GeV and hasn’t gained or lost those 5 vanity giga-electron volts those health and fitness magazines for subatomic particles are obsessed with. A field of axions could slightly warp space and time, making all sorts of subtle changes that cumulatively have a big effect on the universe,which also makes them great candidates for dark matter.

All right, so people have been predicting the existence of axions for decades and they seem to fill out so many blank spots in cosmology so well that they might be the next biggest thing in all of physics. But do they actually exist? Well, they might. We think some may have been found in anomalous X-ray emissions from the sun, though not every expert agrees, and there are a few experiments hunting for stronger evidence of them. Should we find unequivocal proof that they exist just as the equations predict they should, with the right mass and charge, one could argue you would have a discovery even bigger than that of the Higgs because it solves three massive problems in cosmology and quantum mechanics in one swoop. But until we do, we’re still stuck with the alarming thought that after the LHC ramps up to full power, it wouldn’t show us a new particle or evidence of new physics, and future colliders would never have the oomph to cover the enormous void between Standard Model and gravitational particles. And this is why it would be so great if we detect axions or the LHC manages to break particle physics as we know it…